The fashion chief bought a 5,400-square-foot, midcentury modern in California as a vacation home

Fashion company VPL's name stands for "Visible Panty Line." The idea is that it erases the boundaries between underwear and outerwear by incorporating lingerie into clothing, like a $185 jersey tunic with a crisscross bra-shaped top and bright blue elastic straps. "It's bringing the inside out," explained Kikka Hanazawa, the company's 43-year-old president.

Bringing the inside out is also what Ms. Hanazawa did when she bought a 5,400-square-foot, midcentury modern in Montecito, Calif., as a vacation...